From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 682B4C432BE for ; Fri, 20 Aug 2021 15:53:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4644A60FE6 for ; Fri, 20 Aug 2021 15:53:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241181AbhHTPy3 (ORCPT ); Fri, 20 Aug 2021 11:54:29 -0400 Received: from fllv0016.ext.ti.com ([198.47.19.142]:59444 "EHLO fllv0016.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238296AbhHTPy1 (ORCPT ); Fri, 20 Aug 2021 11:54:27 -0400 Received: from lelv0266.itg.ti.com ([10.180.67.225]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id 17KFrV6X013962; Fri, 20 Aug 2021 10:53:31 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1629474811; bh=J/vo8B832cJn3Xv3wVaMKao5wbidMkr/qtLCpo6Q50Y=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=QVYif6d1Mo5bFWQg+KYT7rSwP1/aIJ2Jvatme+F76Na7N6mD12Eht0N7jOh/2HEyl 3/7iASVRwUng3O3G92L5zdPT3xz/yjvGiyBQ/c598VNu1mgxtSI2JcbH81r6UpX5Xw woAaV35e5r7vnHlUIBYL3hpndsHfGUU4qHFeDyx4= Received: from DLEE103.ent.ti.com (dlee103.ent.ti.com [157.170.170.33]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 17KFrVi7076792 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 20 Aug 2021 10:53:31 -0500 Received: from DLEE114.ent.ti.com (157.170.170.25) by DLEE103.ent.ti.com (157.170.170.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Fri, 20 Aug 2021 10:53:30 -0500 Received: from lelv0326.itg.ti.com (10.180.67.84) by DLEE114.ent.ti.com (157.170.170.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2 via Frontend Transport; Fri, 20 Aug 2021 10:53:30 -0500 Received: from [10.250.232.95] (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0326.itg.ti.com (8.15.2/8.15.2) with ESMTP id 17KFrQdP081560; Fri, 20 Aug 2021 10:53:27 -0500 Subject: Re: [PATCH 08/13] mtd: spinand: Reject 8D-8D-8D op_templates if octal_dtr_enale() is missing in manufacturer_op To: Miquel Raynal CC: Richard Weinberger , Vignesh Raghavendra , Mark Brown , Patrice Chotard , Boris Brezillon , , , , Pratyush Yadav References: <20210713130538.646-1-a-nandan@ti.com> <20210713130538.646-9-a-nandan@ti.com> <20210806210146.3358a85b@xps13> <4d428465-59d7-6771-8344-c5090add2a06@ti.com> <20210820141413.6c519255@xps13> <11d173f2-2011-d029-e905-a10fdd0f2b85@ti.com> <20210820163802.529482dd@xps13> From: Apurva Nandan Message-ID: <68eb2817-1df8-464b-aef8-15e9c9adfead@ti.com> Date: Fri, 20 Aug 2021 21:23:25 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210820163802.529482dd@xps13> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Miquèl, On 20/08/21 8:08 pm, Miquel Raynal wrote: > Hi Apurva, > > Apurva Nandan wrote on Fri, 20 Aug 2021 19:24:34 > +0530: > >> Hi Miquèl, >> >> On 20/08/21 5:44 pm, Miquel Raynal wrote: >>> Hi Apurva, >>> >>> Apurva Nandan wrote on Fri, 20 Aug 2021 16:56:50 >>> +0530: >>> >>>> On 07/08/21 12:31 am, Miquel Raynal wrote: >>>>> Hi Apurva, >>>>> >>>>> Apurva Nandan wrote on Tue, 13 Jul 2021 13:05:33 >>>>> +0000: >>>>> >>>> The SPI NAND core doesn't know how to switch the flash to Octal DTR >>>>>> mode (i.e. which operations to perform). If the manufacturer hasn't >>>>>> implemented the octal_dtr_enable() manufacturer_op, the SPI NAND core >>>>>> wouldn't be able to switch to 8D-8D-8D mode and will also not be able >>>>>> to run in 1S-1S-1S mode due to already selected 8D-8D-8D read/write >>>>>> cache op_templates. >>>>>> >>>>>> So, avoid choosing a Octal DTR SPI op_template for read_cache, >>>>>> write_cache and update_cache operations, if the manufacturer_op >>>>>> octal_dtr_enable() is missing. >>>>> >>>>> After looking at your previous commit I don't see why this patch would >>>>> be needed. octal_dtr_enable() only updates the mode when it succeeds so >>>>> I don't think this patch is really needed. >>>>> >> >>>> I added it to prevent any errors happening dues to a missing implementation of octal_dtr_enable() from manufacturer driver side. >>>> So, if the manufacturers skips the octal_dtr_enable() implementation, we want the spinand core to run in 1s-1s-1s mode. >>> >>> I still don't get the point: you fail the probe if the octal bit is >>> enabled but the manufacturer did not implement octal_dtr_enable(), so >>> how could we have issues? Maybe I am overlooking something though, but >>> this seemed completely redundant to my eyes so far. >>> >> >> Okay, I feel this may be redundant. This is for the case when the manufacturer has added Octal DTR read/write/update cache variants but hasn't implemented the octal_dtr_enable() method. >> >> Without this patch, the probe would fail, if the manufacturer did not implement octal_dtr_enable(). But after using this patch, spinand can still use the chip in 1s-1s-1s mode in that case and just skip the Octal DTR op variants during the selection. And also the probe would succeed. > > Unless I am overlooking something with this series applied > (with or without this patch) the possibilities are: > - no octal bit -> continue as before > - octal bit and vendor callback -> uses octal mode > - octal bit and no vendor callback -> will return an error from > spinand_init_octal_dtr_enable() which will fail the probe (patch 7) > > Anyway we have a choice: > - Either we consider the tables describing chips as pure descriptions > and we can support these chips in mode 1-1-1 (will require changes in > your series as this is not what you support as far as I understand > the code) > - Or we consider these tables as "what is currently supported" and in > this case we just fail if one adds the octal bit without any callback > implementation. > > I think the latter is better for now. We can update this choice later > if needed anyway. > Yes, I fully agree with the latter. I will drop this patch in the v2. Thanks! >> >>>> >>>> Read/write/update op variant selection happens in select_op_variant(), much before octal_dtr_enable(). So just check if there is a definition of octal_dtr_enable in manufacturer ops and then only use 8D op variants. >>>> >>>> Removing this wouldn't break anything in the current implementation. >>>> Do you think we should drop this? >>>> >>>>>> >>>>>> Signed-off-by: Apurva Nandan >>>>>> --- >>>>>> drivers/mtd/nand/spi/core.c | 7 ++++++- >>>>>> 1 file changed, 6 insertions(+), 1 deletion(-) >>>>>> >>>>>> diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c >>>>>> index 19d8affac058..8711e887b795 100644 >>>>>> --- a/drivers/mtd/nand/spi/core.c >>>>>> +++ b/drivers/mtd/nand/spi/core.c >>>>>> @@ -1028,6 +1028,8 @@ static int spinand_manufacturer_match(struct spinand_device *spinand, >>>>>> if (id[0] != manufacturer->id) >>>>>> continue; >>>>>> >> + spinand->manufacturer = manufacturer; >>>>>> + >>>>>> ret = spinand_match_and_init(spinand, >>>>>> manufacturer->chips, >>>>>> manufacturer->nchips, >>>>>> @@ -1035,7 +1037,6 @@ static int spinand_manufacturer_match(struct spinand_device *spinand, >>>>>> if (ret < 0) >>>>>> continue; >>>>>> >> - spinand->manufacturer = manufacturer; >>>>>> return 0; >>>>>> } >>>>>> return -ENOTSUPP; >>>>>> @@ -1097,6 +1098,10 @@ spinand_select_op_variant(struct spinand_device *spinand, >>>>>> unsigned int nbytes; >>>>>> int ret; >>>>>> >> + if (spinand_op_is_octal_dtr(&op) && >>>>>> + !spinand->manufacturer->ops->octal_dtr_enable) >>>>>> + continue; >>>>>> + >>>>>> nbytes = nanddev_per_page_oobsize(nand) + >>>>>> nanddev_page_size(nand); >>>>>> > > Thanks, >>>>> Miquèl >>>>> >>>>> ______________________________________________________ >>>>> Linux MTD discussion mailing list >>>>> http://lists.infradead.org/mailman/listinfo/linux-mtd/ >>>>> >> >>>> Thanks, >>>> Apurva Nandan >>> >>> >>> >>> >>> Thanks, >>> Miquèl >>> >> >> Thanks, >> Apurva Nandan > > Thanks, > Miquèl > Thanks, Apurva Nandan